These woofers, spaced 180 degrees apart in a 'BalancedForce' configuration, operate in exact opposition, to nullify distortion causing cabinet vibrations and deliver pure bass energy. Traditional subwoofer enclosures suffer from an equal and opposite reaction to the cone's movement, generating acoustic vibrations within the cabinet. You feel this by touching the cabinet. Although the "physics" of this phenomenon actually cause a subwoofer cabinet to resonate or even dance, most subwoofer designers apply weight or mass to the cabinet to minimize such disturbances, but still leave one byproduct—"smeared bass". BalancedForce is an elegantly simple solution that removes the variable of cabinet vibration contributions from the acoustic equation.

Advanced Ultra-Efficient D-Class Amplifier

BalancedForce subs match powerful proprietary switching amps with incredible woofer drivers resulting in tightly defined bass while keeping distortion at the lowest possible levels. The BalancedForce 210 features an 850-watt class-D switching amplifier capable of a 1700-watt peak operating at over 90% efficiency. BalancedForce 212 features dual 850-watt amplifiers (one for each woofer) with a total system power of 1700-watts (3400-watts system peak).

PBK Room Correction & 25Hz Level Control

Although correct placement plays a key role in optimizing subwoofer performance, positioning a subwoofer often requires compromises. The optional MartinLogan Perfect Bass Kit (PBK, sold separately) uses a computer and microphone to listen throughout the listening environment and tailor the sub's performance to the unique acoustic properties of a room—resulting in clean, powerful bass down to the lowest frequencies.

Additionally, a built-in 25Hz level control allows listeners to adjust subwoofer output by ±10dB and compensate for excessive room gain by cutting output in the 20- to 30-Hz range, or to accentuate the feeling of deep-bass energy by augmenting those frequencies.

Although ports are a convenient and cost-effective way of increasing low-frequency output, their reliance on resonant energy impairs bass quality. The BalancedForce subwoofer's sealed system exhibits less transient-blurring group delay while maintaining smooth, consistent response, regardless of music or movie source material.

Simultaneous LFE and 2-Channel Connections for Seamless System Integration

Robust connection and control systems allow simultaneous connection of both 2-channel stereo music and multi-channel home theater and allows each source to have individual crossover and level settings, giving listeners a perfect performance in every application. LFE input via RCA or XLR effectively uses no low-pass filter, leaving crossover control to the processor. Left and right RCA, XLR, and speaker level inputs integrate discrete user-adjustable or speaker specific custom-installed audiophile grade low-pass filters allowing different level and crossover points when playing back two channel music.

Top mounted controls are discretely hidden beneath a smoked glass accent panel allowing easy access to fine tune the subwoofer's settings. Access the top mounted control panel by pushing firmly on the smoked glass panel. You'll find all of your standard subwoofer controls like Level, Low-Pass Filter and Phase, plus some that are unique to MartinLogan.

A unique tone sweep feature assists users in locating areas in listening rooms where troublesome rattles or resonances may occur. A single press of a button allows listeners to initiate a tone sweep from 120–20Hz. If a rattle or resonance occurs in the room a second press of the button holds the current frequency allowing the listener to investigate and identify the source.

An 'On/Auto (Trigger)/Off' switch controls the subwoofer's energy saving feature. The 'On' setting prevents the sub from entering energy saving mode. When set to 'Auto (Trigger)', the sub will turn on when a music signal is detected and off after several minutes without a signal. If a 12-volt trigger is connected, the triggering device will turn the subwoofer on and off.

Further flexibility is afforded by custom energy transfer coupler (ETC™) spikes, which can enhance stability on thick carpets, or create tighter coupling between subwoofer and floor to enhance overall sound quality.